The invention relates to the provision of character data for use by an embroidery machine, and in particular, but not exclusively, to the conversion of font character data to embroidery machine readable data for selectable inclusion by an embroidery machine in an embroidery design.
Embroidery designs, when created using computer software, are typically defined by many small geometric or enclosed curvilinear areas. Each geometric area is defined by a single embroidery data object comprising information such as the object outline, stitch type, colour and so on.
For example, a rectangular area of satin stitches might be defined in an embroidery object by the four control points that make up its four corners, while a circular area of fill stitches might be defined by two control points typically the centre of the circle and a point indicating the radius. A more complex shape would normally be defined by many control points, spaced at intervals along the boundary of the shape. These control points may subsequently be used to generate a continuous spline or other curve approximating the original shape.
Having generated an object-based design description, the embroidery objects are converted into a vector-based stitch design which is then used to control an embroidery machine. Such stitch designs contain a sequence of individual stitch instructions to control the embroidery machine to move an embroidery needle in a specified manner prior to performing the next needle insertion. Apart from such vector data, stitch instructions may also include data instructing the embroidery machine to form a thread colour change, a jump stitch or a trim.
It is frequently desirable to incorporate letters, numbers and similar characters into embroidery designs. To this end, it is known to provide embroidery design software for use on a personal computer which includes font data for incorporation into an embroidery object-based description of a design. The object-based description is usually converted by the embroidery design software into a stitch instruction description of the design for subsequent downloading to and stitching out by an embroidery machine. Alternatively, the object-based description may be converted to a stitch instruction description after downloading to a embroidery machine having a sufficiently powerful computer processor to handle the complex conversion process.
The font data accessible to the embroidery design software may be provided as conventional TRUETYPE® brand font, OPENTYPE® brand font, POSTSCRIPT® brand font or other known kinds of computer font which are converted to embroidery objects or stitch instructions by the design software, or which are already available to the software in the form of embroidery objects or stitch instructions. In either case, known embroidery design software incorporates the required character data into the overall design to be stitched before export to the embroidery machine.
Recently, embroidery machines have been manufactured with increasingly sophisticated embroidery design software on board, as the cost of incorporating the required electronics into such machines has fallen. It is known, for example, to provide an embroidery machine having a non-volatile memory containing stitch instruction data relating to all the characters of a particular font, at a particular or several particular scalings.
It is also known to provide such stitch instruction data on a floppy disk which can be read by an embroidery machine, thereby enabling a machine user to gain access to a wide variety of stitchable fonts. To ensure that the characters are as neat and tidy as possible when stitched out, the stitch instruction data is defined by a professional designer working on one scaling of each character of each font at a time. The stitch instructions, once defined in this way, are not generally scalable to define characters of different sizes as this would lead to problems such as over filling, under filling, fabric distortion and inappropriate embroidery thickness on stitching out.
As embroidery machines carry computer processors of increasing power, it would be desirable to provide users of such machines with more flexible ways of incorporating font characters into their embroidery designs. The present invention seeks to address this need, and to overcome problems and disadvantages of the related prior art.